Apparatus for carrying out spectroscopic analysis generally includes a source of radiation, typically infrared or near infrared (NIR) radiation, in the case of FT-IR spectroscopy. The Apparatus includes suitable optics for directing the radiation from the source to the location of a sample under investigation and for collecting radiation reflected from or transmitted through the sample for subsequent analysis. It is common in such apparatus to provide an output port to which can be coupled a probe, whereby the probe can be used to receive radiation from the source and direct it to a remote location for carrying out spectroscopic analysis. Such probes generally include one or more optical fibers within which the radiation can propagate. Examples of known probes are described in W092/09881 and EP-A-0652429. In these known arrangements the source of analysing radiation and the detector of the analysing radiation are both located in the main spectrometer housing which means that the analysing radiation has to propagate twice along the length of the fiber or fibres. Such arrangements suffer from poor efficiency in respect of the collection of the diffusely reflected radiation. The present invention is concerned with an improved design of probe.